1. Field of the Invention
The present invention relates to composite vibration diaphragm technology and more particularly, to a method for making a composite vibration diaphragm by utilizing the integratable characteristic between a hot melt adhesive and a thermosetting adhesive to let a powered reinforcing material be uniformly bonded to a vibration diaphragm.
2. Description of the Related Art
The development of smart phones leads to the development trend of micro speaker. In order to output sounds having superior acoustic characteristics, a variety of diaphragm materials have been continuously developed. Some of speakers adopt a composite diaphragm design.
The conventional method for making a composite vibration diaphragm is achieved by: (a) mixing alumina, silica, carbon nanotubes or any other reinforcing material uniformly in an adhesive (such as epoxy resin or any other thermosetting resin); (b) subsequently applying the mixture on the surface of a diaphragm material, and then baking the mixture coated diaphragm material in a hot air oven to cure the reinforcing material and the thermosetting resin; and (c) finally cooling down the composite vibration diaphragm thus obtain. However, because said reinforcing material is porous nano powder particles, it exhibits very poor adhesion to adhesive. Thus, the reinforcing material may drop from the vibration diagram material easily upon a severe vibration or impact of environmental factors, affecting the physical characteristics of the composite diaphragm. Therefore, it is disadvantageous to the acoustic properties of the output sound of the speaker.